Later, he was co-founder and executive director of the United Neighborhood Organization (UNO) where he led a successful campaign to help 12,000 immigrants become naturalized citizens and register to vote.
[2] One of Solis's first actions was to present Angelo J. LaPietra, the founder of the Old Neighborhood Italian American Club at 31st and Shields, a plaque and reward that recognized him as the leader of the community and 25th Ward.
As alderman, Solis focused on job creation and physical improvements in the 25th Ward (Lower West Side) such as expanded National Museum of Mexican Art in Pilsen, the Ping Tom Memorial Park in Chinatown, and a rehabilitation of the Archer Court Senior housing development.
Solis also encouraged and negotiated with the International Produce Market and American Linen Company to stay and/or locate in the 25th Ward's Planned Manufacturing District (PMD) which has brought and continues to bring jobs and capital to the community.
[5] Shortly after his retirement announcement, it was reported that Solis was secretly recording fellow alderman Ed Burke, who had been charged with corruption.